Height adjustable caster mechanism



K. K. KESLING ET AL 3,534,430

HEIGHT ADJUSTABLE CASTER MECHANISM Oct. 20, 1970 2 Sheets-Sheet 1 FiledApril 5, 1969 INVENTORS liez'i'h Ii. liesl 1 219,6

BY J12 [z'vesay ATTORNEY Oct. 20, 1970 KESUNG ET AL 3,534,430

HEIGHT ADJUSTABLE CASTER MECHANISM Filed April 5, 1969 2 Sheets-Sheet 2Zfl g5 56 Z7 I LWENTORS Keith Hfiesliugfi 7 BY J10. [z'vesay ?.Z.Zam/

ATTORNEY United States Patent HEIGHT ADJUSTABLE CASTER MECHANISM KeithK. Kesling, Dayton, and J. D. Livesay, Tipp City,

Ohio, assignors to General Motors Corporation, De-

troit, Mich., a corporation of Delaware Filed Apr. 3, 1969, Ser. No.813,054 Int. Cl. B60b 33/06 US. C]. 1634 3 Claims ABSTRACT OF THEDISCLOSURE In preferred form, a height adjustable retracting castermechanism for a refrigerator comprising: a bracket containing a camsurface; a roller secured to the bracket; and an adjusting assemblyincluding a bolt extending through the refrigerator frame having thereona coupling assembly engaging the camming surface of the bracket to causepivotal movement with respect to the frame. The coupling assembly slideson the cam surface minimizing the effort required to turn the adjustingbolt.

This invention relates to a height adjustable retracting castermechanism, and more particularly to a caster mechanism for a heavydomestic appliance such as a refrigerator or the like. The desirabilityof equipping heavy domestic appliances or furniture with casters formobility has long been evident. This enables the appliance or otherheavy object supported by the casters to be easily moved.

Thus, supporting surfaces on which dust, food particles collect can becleaned periodically without great effort. Furthermore, estheticconsiderations often dictate that furniture and appliances be rearrangedoccasionally.

In clean modern design of household appliances it is desirable thatcasters be equipped with retracting mechanisms hidden by the appliancecabinet. Caster retractability is desirable in order to allow cornerlocated fixed support leveling feet to hold the appliance in place whenthe casters are raised. When they are lowered the appliance feet will belifted from the floor to allow quick roller movement on the casters.Also, normally the casters are raised from the floor and this preventssupporting rollers of certain synthetic plastics from taking a permanentset.

It is also desirable that retractable casters be easily adjustable froma retracted raised position to a lowered surface engaging position sothat a housewife can easily perform the adjustments with simple tools.Therefore, a good retractable caster design should be constructed torequire only a minimal effort to perform the adjustment.

Occasionally, space limitations above the supported device, prohibit thedevice from being raised any appreciable height; accordingly, a goodretractable mechanism should be adjustable over a wide range of usableheights.

Applicants invention provides a novel arrangement of simple parts whichfunction to produce the aforesaid desirable attributes in a readilyinstalled retractable caster mechanism.

Accordingly, it is an object of this invention to provide a heightadjustable retracting caster mechanism which may be adjusted over a widerange of usable heights including a lowered ground engaging position atwhich a supported device can be easily moved and a raised retractedposition above ground.

Another object of this invention is to provide an adjustable retractingcaster mechanism that is adapted for inclusion on heavy devices such asfloor mounted domestic appliances and can be easily moved into aretracted position inside the device so that corner feet on the devicehold it in place; and further can be positioned in a lower "ice groundengaging position to raise the feet to permit the device to be easilyrolled from a set position.

Further objects and advantages of the present invention will be apparentfrom the following description, references being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

FIG. 1 is a partially broken away perspective view of a lower corner ofa refrigerator including the invention;

FIG. 2 is a fragmentary side view of the retractable caster mechanism ofthe present invention;

FIG. 3 is a vertical sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is an enlarged, fragmentary vertical sectional view taken alongline 4-4 of FIG. 3;

FIG. 5 is an enlarged, horizontal sectional view taken along a line 55of FIG. 3;

FIG. 6 is a view in horizontal section taken along the line 66 of FIG. 2looking in the direction of the arrows; and

FIG. 7 is a side elevational view like FIG. 2 which shows the castermechanism in its raised or retracted position.

Referring now to the drawings and more particularly to FIGS. 1 and 2; arefrigerator 12 is shown having a corner frame 14. Frame 14 has avertical wall 16 and a horizontal bottom wall 18. Side Wall 16 containsa circular opening 19 near bottom wall 18.

Rigidly affixed by conventional means, such as spot welding or the like,to wall 16 and wall 18 is a reinforcing gusset 20 which comprises acylindrical base 21 and an essentially L-shaped upper member 22 formedintegrally therewith. Cylindrical base 21 has an upstanding verticalside 23 having three pair of spaced apart openings 24, 25 and 26therethrough and a horizontal bottom portion 27 containing a relativelylarge rectangular opening 28.

L-shaped member 22 has a vertical segment and spaced apart horizontalflanges 29 and 30 which extend to one side. Flange 30 contains a smallrectangular block 31 secured thereto having a vertically directedthreaded bore 32 which threadably receives a corner foot or leg 33 thatsupports the weight of the refrigerator.

Each foot 33 in the refrigerator is associated With a retractable heightadjustable caster mechanism 34. Each mechanism 34 has an upstandingbracket 35 having a pair of identically shaped side walls 36. Side walls36 are substantially truncated in shape and have a longitudinal centerline 38, a relatively wide lower base segment 40, an intermediatesegment 42 and a relatively narrow top segment 44. Base segments have anaverage width approximately /3 the longitudinal length of side walls 36measured along center line 38. Side walls 36 are integrally joined by atop segment interconnecting member 46 and an intermediate segmentinterconnecting member 48.

Base segments 40 each have frame pivoted edge sections 50 and 52. Moreparticularly, section 50' contains an opening 54, and section 52contains an opening 56. A pin or shaft 58 having a longitudinal axis 59is positioned in openings 56 and pivotally secures bracket 34 to gusset20 at openings 24 therein. A shaft 60 having a longitudinal center line61 is positioned in openings 54 and rotatably secures a nylon roller 62to bracket 35.

A cam surface 64 on bracket 35 is concaved inwardly toward center line38 and is integrally formed between interconnecting members 46 and 48adjacent each top segment 44. As best seen in FIG. 2, surface 64 has achord length to segment height ratio of approximately 8:1 with its chordlength being approximately of the longitudinal length of side walls 36measured along center line 38. An elongated opening 66 in surface 64 isbounded 3 by an upper surface 68 and a lower surface 70. As shown, theopening 66 is located approximately in the center of cam surface 64.Elongated opening 66 is substantially elliptically shaped and has itsmajor axis essentially parallel to center line 38.

An elongated adjusting bolt 72 has a longitudinal center line 73, a head74 positioned exteriorly of vertical wall 16, and a shaft 76. Shaft 76,which has a diameter approximately the distance of opening 66 along itsmajor axis, contains a threaded end 78 positioned interiorly of frame 14through opening 19. Threaded end 78 of shaft 76 is slidably locatedwithin opening 19 and elongated opening 66.

Threadably positioned on end 78 is a rectangular nut 80 having anoutside face 81, and a face 82 against surface 64. Nut 80 also has apair of vertical side edges 83 and a pair of horizontal top and bottomedges 84. A coupling member 86 loosely couples nut 80 and cammingsurface 64 together.

As best seen in FIGS. 4 and 5, coupling member 86 comprises arectangular body 88 positioned between nut 80 and surface 64, a pair ofnut-retainer arms 90, and a pair of cam-guide arms 92. Body 88 has acircular opening 94 for receiving shaft 76 and a pair of tabs 96-. Tabs96 which are located adjacent opposite edges of body 88 are angularlydirected toward bolt 72 and each terminates in close spaced relationshipto nut 80 for loosely retaining it against lateral movement with respectto arms 90.

Arms 90 extend generally perpendicular from body 88 adjacent and inclose space relationship to vertical edges 83 of nut 80. Arms 90 alsohave bent over ends 98 in close spaced relationship to front face 81 toloosely connect nut 80 against movement from cam 64. Thus the member 86is loosely coupled to nut 80.

Arms 92 which extend generally perpendicularly from body 88 on a side ofbody 88 opposite to arms 90 each contain a tab 100. Tabs 100 are eachangularly directed toward surface 64 and terminate in close spacedrelationship thereto. Tabs 100 and arms 92 fit around surface 64 as bestseen in FIG. 5 to be loosely coupled with respect thereto.

Turning now to a discussion of the operation of this preferredembodiment, in the solid line position of FIG. 7 the roller 62 isinitially retracted. The leveling foot 33 is threadably positioned inbore 32 so that it initially will carry the weight of frame 14.Adjusting bolt 72 is positioned such that threaded end 78 will rest onlower surface 70 of elongated opening 66.

As bolt 72 is rotated in a first or second direction, it is apparentthat nut 80 will advance or recede along threaded end 78 of shaft 76.When bolt 72 is rotated in a first direction such that nut 80 advancestoward head 74, nut 80 will eventually cause body 88 of coupling member86 to bear against the cam surface 64. As bolt 72 is rotated further inthe first direction, bracket 35 will begin to pivot downwardly about pinor shaft 58. Nut 80 and coupling member 86 will cam upwardly alongsurface 64 causing bolt 72 to shift upwardly to assume a more horizontalposition. This lost motion of member 86 and nut 80 with respect to camsurface 64 allows bracket 35 to pivot freely without binding againstmember 86.

The above discussed relationships will be essentially continued asroller 62 passes through rectangular opening 28 to engage the framesupporting surface. Further travel of roller 62 will cause the adjacentfoot 33 to be raised from the surface.

If bolt 72 is rotated in a second direction, nut 80 will recede awayfrom head 74 along shaft 76 carrying coupling member 86 in the samedirection. Bracket 35 will begin to pivot upwardly and member 86, guidedby cam-guide arms 92 and angular tabs 100' will cam downwardly onsurface 64. Continued rotation of head 74 in the second direction willeventually raise roller 62 off the supporting surface and reengageleveling foot 33 therewith. Further rotation will retract the rollerfurther into frame 14.

It should be apparent that the distance that a bracket 34 is pivoted todisengage a leveling foot 33 from a supporting surface can be adjustedover a wide range. It should also be apparent that frame 14 can besupported and moved on roller 62 in a plurality of heights up to amaximum height which exist when shaft 76 engages upper surface 68 ofelongated opening 66.

Further, it should be apparent that the loose coupling of bracket 34with adjusting bolt 72 which is maintained by cam surface 62 and member86 over the entire adjustment range minimizes the adjustment effortrequired.

It should also be apparent that rivet 58 can be located in openings 24,25 or 26 of base 21. This allows gusset 20 to be used on any corner orside of a supported device.

While the embodiment of the present invention as herein disclosedconstitutes a preferred form it is to be understood that other formsmight be adopted.

We claim:

1. An adjustable, retractable caster mechanism for use in slidablysupporting corners of a domestic appliance comprising: a frame; anupstanding bracket having a side wall with a base segment and a topsegment, a cam surface integrally formed on said bracket adjacent saidtop segment, said base segment having first and second edges, said camsurface containing an opening; a first shaft pivotably securing saidbase segment to said frame adjacent to said first edge; a roller, asecond shaft rotatably securing said roller to said base segmentadjacent to said second edge; a third shaft having a head positionedexteriorly of said frame and a threaded end positioned interiorly ofsaid frame, said threaded end slidably contained in said opening of saidcam surface; a nut threadably positioned on said third shaft; couplingmeans for interconnecting said nut and said cam surface to causethreaded movement of said third shaft to pivot said bracket about saidfirst shaft and raise and lower said roller within said frame, coactingmeans on said coupling means and said cam surface for minimizing theefforts required to turn said third shaft during pivotal movement ofsaid bracket.

2. An adjustable retractable caster mechanism for use in slidablysupporting the corner of a domestic appliance comprising: a frame; anupstanding bracket having a side wall with a base segment and a topsegment, a cam surface integrally formed on said bracket adjacent saidtop segment, said base segment having first and second edges, said camsurface containing an elongated opening; a first shaft pivotallysecuring said base segment to said frame adjacent to said first edge; aroller, a second shaft rotatably securing said roller to said basesegment adjacent to said second edge; a third shaft having a headpositioned exteriorly of said frame and a threaded end positionedinteriorly of said frame, said threaded end slidably contained in saidopening of said cam surface; a nut threadably positioned on said thirdshaft; coupling means for interconnecting said nut and said cam surfaceto cause threaded movement of said third shaft to pivot said bracketabout said first shaft and raise and lower said roller within saidframe, said coupling means including a body segment positioned betweensaid nut and said cam surface having a plurality of arms extendinggenerally perpendicularly therefrom in close spaced relationship to saidcam surface and said nut, coacting means on said coupling means and saidcam surface for minimizing the effort required to turn said third shaftduring pivotal movement of said bracket including a surface on said camsurface convexly formed with respect to said nut and angularly directedtabs on said arms terminating in close spaced relationship to said nutand said cam surface.

3. An adjustable retractable caster mechanism for use in supporting thecorner of a domestic appliance on a roller bearing comprising: a frame,an upstanding bracket having a side wall with a base segment, anintermediate segment, and a top segment, a cam surface integrally formedon said bracket adjacent said head segment, said base segment havingfirst and second edges, said cam sur face containing a substantiallyelliptically shaped opening; a first shaft pivotally securing said basesegment to said frame adjacent to said first edge; a roller; a secondshaft rotatably securing said roller to said base segment adjacent tosaid second edge; a third shaft having a head positioned exteriorly ofsaid frame and a threaded end positioned interiorly of said frame, saidthreaded end slidably contained in said elliptical opening of said camsurface, the diameter of said shaft being substantially smaller than thediameter of said elliptically shaped opening measured along the majoraxis thereof; a nut threadably positioned on said third shaft; couplingmeans for interconnecting said nut and said cam surface to causethreaded movement of said third shaft to pivot said bracket about saidfirst shaft and raise and lower said roller within said frame includinga coupling member having a body segment positioned between said nut andsaid cam surface, said body segment having a plurality of arms extendinggenerally perpendicularly therefrom in close spaced relationship to saidcam surface and said nut, a surface on said cam surface formed convexlytoward said nut and angularly directed tabs on said arms terminating inclose spaced relationship to said nut and said cam surface forminimizing the effort required to turn said third shaft during pivotalmovement of said bracket.

References Cited UNITED STATES PATENTS 3/1969 Hupfer 1632 9/1958 Matter1632 U.S. Cl. X.R. 1619

